By classification, this is one of the Green Algae, and it has green chlorophyll; that underlying colour is simply masked by the presence of large amounts of orange pigments (carotenoids).

Trentepohlia also occurs within many lichens. A lichen is an association of a fungus with at least one other species that performs photosynthesis: in about 60% of lichen species, the latter role is filled by unicellular green algae; in about 30%, by Trentepohlia algae; and in about 10%, by cyanobacteria (such as Nostoc – Link ).